Employment Tax US Staff Remote UK: Specialist Guide 2026 |

Why This Comes Up

The conversation usually starts with an email from HR. A US employee — maybe a senior engineer, maybe a regional sales lead — wants to work from a flat in London or Edinburgh for a few months. The employer says yes because remote work is normal now. Six months later, the employee is still in the UK, has rented a flat, and might be eligible for a UK Skilled Worker visa.

Nobody has spoken to a tax adviser. The US payroll keeps running through ADP or Gusto, the federal taxes keep coming out, and everyone assumes the situation is fine. It is not. This tutorial explains the employment tax structure for US employees working remotely in the UK, what causes a UK PAYE requirement, how the income is positioned under the treaty, and what to do if you

 discover the problem mid-flight. For broader US-UK structuring help, see our US-UK cross-border tax advisory service.

What Employment Tax for US Staff Working from the UK Actually Covers

The framework spans three separate UK tax codes that all apply simultaneously. PAYE income tax under the Income Tax (Earnings and Pensions) Act 2003 picks up wages earned while the employee is physically working in the UK. National Insurance under the Social Security Contributions and Benefits Act 1992 applies to those same earnings unless a totalisation certificate exempts the worker. If the UK-based employee establishes a permanent place of business or regularly enters into contracts, the US employer is subject to corporation tax through permanent establishment risk.

The trigger for UK residence is the Statutory Residence Test, set out in FA 2013 Schedule 45. The test has three parts. The automatic UK tests treat anyone who has been in the UK for 183 days or more in a tax year as a resident. The automatic overseas tests provide clear non-residence for limited UK presence. The sufficient ties test catches anyone in between, weighing UK family, accommodation, work, and prior residence days against UK time spent. The HMRC SRT guidance sits at https://www.gov.uk/government/publications/rdr3-statutory-residence-test-srt.

The income side runs alongside the residence side. A US employee who is a UK resident gets taxed on worldwide employment income from the date UK residence starts. A non-resident UK visitor still gets taxed on the part of their salary attributable to UK workdays, unless treaty relief applies. Article 14 of the US-UK Income Tax Treaty exempts employment income from UK tax only if three conditions are met: fewer than 183 UK days in any 12 months, not a UK resident, and a UK permanent establishment does not bear the cost.

NIC and US FICA do not stack under the US-UK Totalisation Agreement, which allows a worker to remain in only one social security system at a time. A certificate of coverage from either the IRS or HMRC keeps the employee within their home system for up to 5 years during a qualifying secondment.

What Changed for 2026

Three developments matter for US companies with UK-based staff in 2026.

First, the UK Employer NIC rate rose to 15 percent from 6 April 2025, and the Secondary Threshold fell to £5,000. For a US employee on a £100,000 equivalent salary working from the UK, that change adds around £2,200 of Employer NIC cost compared to the prior regime. The HMRC NIC rates page sits at https://www.gov.uk/national-insurance-rates-letters.

Second, HMRC's data-matching with US payroll providers has tightened. The Common Reporting Standard exchanges and bilateral CAA arrangements mean HMRC sees ADP and Gusto wage data faster than most US employers expect. A US employee filing a UK Self Assessment return after six months in the UK triggers automatic cross-checks against their US payroll position.

Third, the post-Brexit position on Frontier Workers and the EU Withdrawal Agreement has clarified for US nationals working from the UK. A US employee in the UK is straightforwardly subject to the UK Statutory Residence Test and the bilateral US-UK Totalisation Agreement, with none of the residual EU coordination rules in play. For deeper context on US payroll routes into the UK, see our UK PAYE for US companies guide.

The Three Tax Triggers Every US Employer Should Map

Trigger 1: UK Income Tax and PAYE

A US employee physically working in the UK incurs a UK income tax charge from day one on the portion of salary attributable to UK workdays, regardless of where the employer is or who runs payroll. Once the worker becomes a UK tax resident under the SRT, the charge expands to worldwide employment income.

The complication for US employers is that HMRC expects them to operate PAYE even when they have no UK entity. The legal route is either to register the US company itself for a UK PAYE scheme as a foreign employer, run a shadow PAYE through a Section 690 ITEPA 2003 direction that limits withholding to UK workdays, or push the entire employment relationship to a UK Employer of Record.

Section 690 directions are particularly useful for genuinely split-location workers. A US employer applies to HMRC with an estimate of UK versus non-UK workdays, and HMRC agrees on a percentage of salary on which UK PAYE applies. The remaining percentage stays outside UK PAYE because it relates to non-UK workdays.

Trigger 2: UK National Insurance

National Insurance applies to UK earnings unless a totalisation certificate exempts the worker. A US employee on a temporary UK assignment of up to five years can stay inside US FICA by obtaining a certificate of coverage from the IRS Social Security Administration, which HMRC then accepts as evidence to exempt the earnings from UK NIC.

Without a certificate of coverage, the US employer becomes liable for UK Employer NIC at 15 percent on earnings above the £5,000 Secondary Threshold, and the employee owes UK Employee NIC. Both apply to UK-earned wages from the first payday, and the US employer must find a way to collect and pay HMRC, even without a UK bank account.

Trigger 3: Permanent Establishment Risk

The most expensive trigger sits not with the employee but with the US employer itself. Under Article 5 of the US-UK Income Tax Treaty and the OECD Model framework, a UK-resident employee can create a permanent establishment for the US employer if either of the two tests is met. The fixed place of business test includes dedicated office space, including a home office habitually used as the employee's primary work base. An agency PE test identifies employees with the authority to enter into contracts in the name of the US employer.

A senior engineer working from a London flat for nine months without external customer contact is unlikely to create a PE. A regional sales director who pitches and closes UK deals from the same flat almost certainly does. The consequence of a PE is UK Corporation Tax at up to 25 percent on profits attributable to the UK presence, plus retrospective filings going back to the start of the PE. The HMRC International Manual on PE sits at https://www.gov.uk/hmrc-internal-manuals/international-manual.

How to Handle UK-Based US Staff Step by Step

Step 1 — Run the Statutory Residence Test for the employee. Take the planned UK calendar in twelve-month blocks. Apply the automatic UK tests (183-day, only home in UK, full-time work in UK), the automatic overseas tests, and the sufficient ties test. Decide which tax year the UK residence starts and document the work. The HMRC SRT guidance sits at https://www.gov.uk/government/publications/rdr3-statutory-residence-test-srt.

Step 2 — Apply for a US Totalisation Certificate of Coverage. If the assignment is five years or less and the worker remains a US employee, file Form USA/UK1 with the IRS and the Social Security Administration. The certificate keeps FICA in place and exempts UK NIC. Without it, the US employer takes on UK NIC at 15 percent from day one.

Step 3 — Decide the PAYE route. Three options sit on the table. Register the US company as a foreign employer with HMRC for a direct PAYE scheme. Use a Section 690 ITEPA 2003 direction if workdays are split between the UK and elsewhere. Move the employment to a UK Employer of Record if the employee has effectively relocated.

Step 4 — Run a permanent establishment assessment for the US employer. Look at where the employee physically works, what they do, who they meet, whether they sign contracts, and whether the home or local office could be characterized as a fixed place of business. Document the conclusion. If the risk is meaningful, get a written opinion from a CTA-qualified adviser before HMRC opens an inquiry.

Step 5 — Set up the UK payroll mechanics. If you go direct PAYE, register through HMRC Online Services, get the PAYE reference and Accounts Office Reference, choose UK payroll software (Xero Payroll, BrightPay, IRIS), and configure monthly Real Time Information Full Payment Submissions. If you go EOR, transfer the employment cleanly with proper notice and benefits continuity.

Step 6 — Coordinate the US side. US federal income tax continues to apply to the employee as a US citizen or green card holder, regardless of UK residence. The Foreign Earned Income Exclusion under IRC Section 911 may cover up to $130,000 of foreign earned income in 2025, with the foreign tax credit under IRC Section 901 covering the rest. The IRS Section 911 guidance sits at https://www.irs.gov/individuals/international-taxpayers/foreign-earned-income-exclusion.

Step 7 — Document and review every twelve months. UK residence status can change year on year. PE risk can change as the employee's role evolves. Treaty positions can shift if the assignment length extends. Build a calendar reminder at six and twelve months from the first UK workday and reassess from scratch.

Worked Example: A US Marketing Director Relocates to London

A Boston-based ed-tech company with 240 staff allowed its VP of Marketing to relocate to London in mid-2025 to be closer to family. Annual base salary $245,000, target bonus $60,000, RSU grants vesting quarterly worth roughly $90,000 a year. The CEO signed off informally, HR updated the address on file with ADP, and US payroll kept running unchanged.

We picked up the engagement nine months in. The Statutory Residence Test was clear. The VP had spent 220 UK days in the 2025-26 tax year, and her only home was now in the UK, so she met the automatic UK residence tests from her arrival date in June 2025. UK income tax applied to worldwide employment income from that date — base salary, bonus, and the UK portion of RSU vesting.

No certificate of coverage had been filed. UK Employer NIC at 15 percent on the salary above £5,000 came to approximately £36,000 a year. UK Employee NIC at 8 percent up to the Upper Earnings Limit came to roughly £3,400. UK income tax across the personal allowance, basic, higher, and additional rate bands worked out at around £88,000 on a US salary equivalent of about £196,000 sterling.

The retrospective bill needed to be handled fast. We registered the US company as a foreign employer for UK PAYE, applied for a backdated Section 690 ITEPA 2003 direction (which was rejected because the VP was now fully UK-resident), and moved the employee to a UK PAYE shadow payroll for ongoing months. The catch-up PAYE liability covering June 2025 to March 2026 ran approximately £91,000 in income tax and £39,000 in combined NIC. The foreign tax credit on the US Form 1040 absorbed the bulk of the US side, but the UK position had to be settled in sterling from the US company's bank account via a sponsored UK payments arrangement.

Permanent establishment was the second concern. The VP regularly negotiated marketing partnerships with UK universities and signed framework agreements on behalf of the US employer. We documented the working arrangement, accepted that an agency PE under Article 5 of the US-UK Treaty existed, and registered the US company for UK Corporation Tax with profits attributable to the UK marketing function. The first UK Corporation Tax return showed a modest profit of around £45,000 attributable to the PE, taxed at the marginal relief rate.

The total catch-up cost from nine months of unmanaged UK presence was approximately £148,000 across PAYE, NIC, Corporation Tax, interest, and professional fees — far more than the £15,000 it would have cost if planned properly from June 2025.

Common Mistakes US Companies Make

Assuming US payroll covers the UK position. ADP and Gusto handle US federal and state withholding, not UK PAYE. A US employee working from the UK creates a UK income tax obligation that no US payroll system addresses. The US employer must either register for UK PAYE separately or transfer the employment to a UK Employer of Record.

Letting the 183-day rule decide everything. The 183-day automatic test is one route into UK residence, not the only one. Anyone who makes the UK their only home, or works full-time from the UK for 365 days with significant UK workdays in the relevant tax year, becomes UK-resident through the other automatic tests well before hitting 183 days.

Skipping the Totalisation Certificate. Without a US Social Security certificate of coverage, the US employer pays UK Employer NIC at 15 percent on every pound of UK earnings above the Secondary Threshold from the first payday. The certificate takes four to eight weeks to issue and exempts NIC for up to five years on qualifying secondments. Filing it late means UK NIC liability accrues during the gap.

Treating remote work as temporary indefinitely. A US employee who spent six months "trying out" the UK and is now in year two is not on a short trip. HMRC views the residence position based on actual time and circumstances, not on what the employer hoped would happen. Reassess at six months, twelve months, and every renewal point.

Ignoring PE risk because the employee works from home. A home office can be a fixed place of business for PE purposes under OECD commentary on Article 5, particularly where the employer has no other UK location. The risk is highest when the employee has external-facing authority, such as in sales, business development, or senior commercial roles. The HMRC International Manual on PE sits at https://www.gov.uk/hmrc-internal-manuals/international-manual.

Forgetting state-side US tax shutdowns. A US employee who establishes UK residence may also break their US state tax residence, depending on the state. California, New York, and a few others apply aggressive domicile tests that can keep state tax in place even after UK residence starts. Coordinate the state position with the federal and UK positions in one go.

How US-UK Tax Helps US Employers

Our team holds CTA credentials with the Chartered Institute of Taxation and Enrolled Agent status with the IRS, so the same advisers handle the UK PAYE setup, the US Form 1040 coordination, and the permanent establishment assessment. That matters because every UK-resident US employee creates obligations under three separate tax codes simultaneously, and treating them as separate workflows is where US employers typically lose 4 to 8 weeks of decision time and tens of thousands of pounds in unrecovered foreign tax credits.

A typical engagement runs three phases. Phase one is the diagnostic — Statutory Residence Test working, Totalisation Certificate filing, treaty Article 14 review, PE risk assessment, and US foreign earned income or foreign tax credit modeling. Phase two is the setup — UK PAYE registration or EOR transition, Section 690 direction filing where applicable, US payroll coordination to suppress US state withholding where the employee has properly broken state residence. Phase three is ongoing — monthly UK RTI, annual UK Self Assessment for the employee, US Form 1040 coordination, and yearly reassessment of the residence, NIC, and PE positions. The CIOT directory sits at https://www.tax.org.uk/.

For broader US-UK guidance, see our UK PAYE for US companies guide and our US-UK Treaty advisory service. Get in touch with our team today at or visit https://www.us-uktax.com/ to discuss your remote US staff in the UK.

Conclusion

Three points to take away. First, the Statutory Residence Test under FA 2013 Schedule 45 decides everything that follows, and most US employees in the UK become UK tax-resident long before hitting 183 days because the only-home test catches them first. Run the SRT properly for every employee in the UK for more than three months. Second, the Totalisation Certificate is the single highest-value document in the workflow — a quick filing saves the US employer 15 percent Employer NIC on every pound of UK-period salary for up to 5 years. Third, the risk of a permanent establishment is real and expensive for US employers, particularly when the UK-based employee has external-facing commercial authority. The US staff remote UK employment tax framework rewards early planning and punishes drift. Talk to us at .

Frequently Asked Questions

Q: Does a US employee working remotely from the UK pay UK tax?

A: Yes, on the portion of salary that relates to UK workdays from the first day they physically work in the UK. Once they meet the Statutory Residence Test, UK income tax extends to worldwide employment income. The treaty Article 14 exemption applies only if the employee spends fewer than 183 UK days in 12 months, the employer is not UK-resident, and a UK permanent establishment does not bear the cost. Q: Does my US company need to register for UK PAYE?

A: Yes, if you have any UK-resident employees whose UK earnings are not run through a UK Employer of Record. A US company can register as a foreign employer for a UK PAYE scheme through HMRC Online Services. Registration takes 4 to 8 weeks. Without it, the entire UK income tax obligation falls on the employee through Self Assessment, and the company carries the Employer NIC liability separately.

Q: What is a Totalisation Certificate, and how do I get one?

A: A Totalisation Certificate, formally a Certificate of Coverage, is issued under the US-UK Social Security Agreement to keep a temporary assignee inside their home country's social security system. A US employer files Form USA/UK1 with the IRS and the Social Security Administration for a US employee on assignment to the UK for up to 5 years. HMRC accepts the certificate as evidence to exempt the employee and employer from UK NIC during the certified period.

Q: How does Article 14 of the US-UK Treaty work for remote workers?

A: Article 14 exempts employment income from tax in the country where the work is done if all three conditions are met. The worker spends fewer than 183 days in that country in any twelve months, the employer is not resident in that country, and the employee's permanent establishment in that country does not bear the salary cost of the employee in the UK for fewer than 183 days, paid by a non-UK US employer, with no UK PE, can claim the exemption. Most fail at the 183-day test or the PE test.

Q: Can a remote US employee create a permanent establishment for my US company?

A: Yes, in two ways. A fixed place of business PE arises when an employee habitually uses a UK home or office as a base for company business. An agency PE arises when the employee has authority to enter into contracts in the name of the US employer and habitually exercises it. The PE consequence is UK Corporation Tax on profits attributable to the UK presence at rates up to 25 percent, plus retrospective filings.

Q: What is the difference between Section 690 PAYE and a full UK PAYE scheme?

A: A Section 690 direction under ITEPA 2003 lets a US employer apply UK PAYE only to the proportion of salary relating to UK workdays. The rest of the salary stays outside UK PAYE because it relates to non-UK workdays. A full UK PAYE scheme applies UK PAYE to the whole salary once the employee is UK-resident. Section 690 suits genuinely split-location workers. A full scheme suits fully UK-resident employees.

Q: Does the Foreign Earned Income Exclusion help a US employee in the UK?

A: Yes, up to approximately $130,000 of foreign earned income in 2025 under IRC Section 911, provided the employee meets the bona fide residence test or the physical presence test of 330 days in twelve months. Above that level, the foreign tax credit under IRC Section 901 allows the UK income tax paid to be credited against US federal tax on the same income. The two reliefs are alternatives in some cases and complements in others — the modeling decides which works best.

Q: Can the US-UK Tax handle a US employee who has been in the UK for over a year already?

A: Yes, this is a frequent engagement. We run the Statutory Residence Test backward from the arrival date, file the Totalisation Certificate retrospectively where possible, register the US company for UK PAYE, and negotiate the catch-up PAYE and NIC liability with HMRC, including any penalty reductions for voluntary disclosure. Engagement fees typically range from £4,500 to £15,000 for a single retrospective case, depending on complexity. Contact to discuss your situation.